Levels are saved as ".lvl" files in the levels directory of your Spelunky folder. To share a level with other players here on the forum:

1. Open up the file in a text editor (e.g. Notepad)2. Copy the level data, and then paste it here on the forum.3. Other users can copy that data and save it to a .lvl file to play on their own computer.

I just added the new message icons to label your levels with: EASY, MED, HARD, and OMG! Some of the existing level threads were edited just to show you how they work. The authors of these levels should feel free to change them around if you think I mislabeled them.